Antigenic determinant analysis of FIKK Kinase family to identify novel candidates for diagnosis of Plasmodium falciparum.

The efforts to eliminate malaria require the development of highly sensitive and specific point-of-care diagnostic systems to enable early detection and prevent severe complications associated with the disease. Current rapid diagnostic tests (RDTs) rely on antigens conserved across Plasmodium species or those specific to Plasmodium falciparum and Plasmodium vivax with humans. In the current study, chimeric FIKK (C-FIKK) was generated as a promising target for malaria diagnosis by selecting highly antigenic, species-specific B- and T-cell epitopes of six selected FIKK kinases using IEDB tools, from the N-terminal regions of P. falciparum with no homology with the human counter parts. The antibodies were generated against C-FIKK, purified, and it exhibits high sensitivity with a detection limit of 3 μM for FIKK9.1. In addition, it is very selective for malaria parasite in the presence of bacterial, viral, fungal and algal organisms. Importantly, no cross-reactivity was observed with host blood components or proteins from non-Plasmodium organisms with the purified FIKK9.1. Validation with mock patient samples revealed that the purified antibody could semi-quantitatively detect parasite loads with an average accuracy of 95.45 %. These findings suggest that FIKK kinase-based rapid diagnostic tests is a robust and reliable diagnostic target for malaria detection, paving the way for the development of next-generation diagnostic systems with enhanced sensitivity and specificity.